From patchwork Mon Jun 19 01:46:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Andreas_F=C3=A4rber?= X-Patchwork-Id: 9795025 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 2A4BD600C5 for ; Mon, 19 Jun 2017 01:50:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1333C27FA9 for ; Mon, 19 Jun 2017 01:50:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 061B028066; Mon, 19 Jun 2017 01:50:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [65.50.211.133]) (using TLSv1.2 with cipher AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 4A15927FA9 for ; Mon, 19 Jun 2017 01:50:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=WyG0zoBk+4ZEC8duSj1i6FdX1YBXbD2kkDPCgzosxZc=; b=u4lglA9YbCL5l0 PLwDMe5bZlPySEKapA8pUDuMKpnOv8dn5JPD9fImNv1hrYGoXl5aBWas3t2V2+Y7c8OpqGZA1CLHk 5/qITDQLR9GzR7bj3kgxEMqIjT67Ewgwwfo1TlNzMiumU6YbEfyf7CGcORrB17JB6XUclVS/MQnDd /nkbQHFJNLzMuDRTiEq9dP6HQHE14WF2+N8NfEmqTOI2rSNvLda6P8gBXA/ThyJ3kOXK00ZcrUQIb 5WQjSa2YuSRFllpWA90X1hx+kcvhOYju5UJZM0dqEujK2hWM2WL0Eb45INqqaUPTlU8JbGIYXPbto VK55pp3Bokw1eMJ7Wscg==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.87 #1 (Red Hat Linux)) id 1dMlpZ-00073M-E0; Mon, 19 Jun 2017 01:50:17 +0000 Received: from mx2.suse.de ([195.135.220.15] helo=mx1.suse.de) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dMlma-0005Lp-Gj for linux-arm-kernel@lists.infradead.org; Mon, 19 Jun 2017 01:47:16 +0000 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E8417AC37; Mon, 19 Jun 2017 01:46:50 +0000 (UTC) From: =?UTF-8?q?Andreas=20F=C3=A4rber?= To: Greg Kroah-Hartman Subject: [PATCH v5 08/26] tty: serial: Add Actions Semi Owl UART earlycon Date: Mon, 19 Jun 2017 03:46:40 +0200 Message-Id: <20170619014640.6829-2-afaerber@suse.de> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20170619014640.6829-1-afaerber@suse.de> References: <7fff8813-cea4-0530-bf7b-3d0ad50d6e93@suse.de> <20170619014640.6829-1-afaerber@suse.de> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170618_184712_986283_188FA48B X-CRM114-Status: GOOD ( 19.72 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: support@lemaker.org, =?UTF-8?q?=E5=BC=A0=E5=A4=A9=E7=9B=8A?= , Jonathan Corbet , 96boards@ucrobotics.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Liau , mp-cs@actions-semi.com, linux-serial@vger.kernel.org, =?UTF-8?q?=E5=88=98=E7=82=9C?= , Jiri Slaby , =?UTF-8?q?Andreas=20F=C3=A4rber?= , linux-arm-kernel@lists.infradead.org, =?UTF-8?q?=E5=BC=A0=E4=B8=9C=E9=A3=8E?= Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP This implements an earlycon for Actions Semi S500/S900 SoCs. Based on LeMaker linux-actions tree. Signed-off-by: Andreas Färber --- v4 -> v5: * Squashed documentation (Greg) v3 -> v4: Unchanged v2 -> v3: * Adopted BIT() macro v1 -> v2: * Extended Kconfig help to mention earlycon (Arnd) * Spelled out Actions Semiconductor in Kconfig help * Adopted "actions" vendor prefix Documentation/admin-guide/kernel-parameters.txt | 6 ++ drivers/tty/serial/Kconfig | 19 ++++ drivers/tty/serial/Makefile | 1 + drivers/tty/serial/owl-uart.c | 135 ++++++++++++++++++++++++ 4 files changed, 161 insertions(+) create mode 100644 drivers/tty/serial/owl-uart.c diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index fb311bdccb7b..cc8a6bfcb299 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -961,6 +961,12 @@ must already be setup and configured. Options are not yet supported. + owl, + Start an early, polled-mode console on a serial port + of an Actions Semi SoC, such as S500 or S900, at the + specified address. The serial port must already be + setup and configured. Options are not yet supported. + smh Use ARM semihosting calls for early console. s3c2410, diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 07812a7ea2a4..1f096e2bb398 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1688,6 +1688,25 @@ config SERIAL_MVEBU_CONSOLE and warnings and which allows logins in single user mode) Otherwise, say 'N'. +config SERIAL_OWL + bool "Actions Semi Owl serial port support" + depends on ARCH_ACTIONS || COMPILE_TEST + select SERIAL_CORE + help + This driver is for Actions Semiconductor S500/S900 SoC's UART. + Say 'Y' here if you wish to use the on-board serial port. + Otherwise, say 'N'. + +config SERIAL_OWL_CONSOLE + bool "Console on Actions Semi Owl serial port" + depends on SERIAL_OWL=y + select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON + default y + help + Say 'Y' here if you wish to use Actions Semiconductor S500/S900 UART + as the system console. Only earlycon is implemented currently. + endmenu config SERIAL_MCTRL_GPIO diff --git a/drivers/tty/serial/Makefile b/drivers/tty/serial/Makefile index 53c03e005132..fe88a75d9a59 100644 --- a/drivers/tty/serial/Makefile +++ b/drivers/tty/serial/Makefile @@ -92,6 +92,7 @@ obj-$(CONFIG_SERIAL_STM32) += stm32-usart.o obj-$(CONFIG_SERIAL_MVEBU_UART) += mvebu-uart.o obj-$(CONFIG_SERIAL_PIC32) += pic32_uart.o obj-$(CONFIG_SERIAL_MPS2_UART) += mps2-uart.o +obj-$(CONFIG_SERIAL_OWL) += owl-uart.o # GPIOLIB helpers for modem control lines obj-$(CONFIG_SERIAL_MCTRL_GPIO) += serial_mctrl_gpio.o diff --git a/drivers/tty/serial/owl-uart.c b/drivers/tty/serial/owl-uart.c new file mode 100644 index 000000000000..1b8008797a1b --- /dev/null +++ b/drivers/tty/serial/owl-uart.c @@ -0,0 +1,135 @@ +/* + * Actions Semi Owl family serial console + * + * Copyright 2013 Actions Semi Inc. + * Author: Actions Semi, Inc. + * + * Copyright (c) 2016-2017 Andreas Färber + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define OWL_UART_CTL 0x000 +#define OWL_UART_TXDAT 0x008 +#define OWL_UART_STAT 0x00c + +#define OWL_UART_CTL_TRFS_TX BIT(14) +#define OWL_UART_CTL_EN BIT(15) +#define OWL_UART_CTL_RXIE BIT(18) +#define OWL_UART_CTL_TXIE BIT(19) + +#define OWL_UART_STAT_RIP BIT(0) +#define OWL_UART_STAT_TIP BIT(1) +#define OWL_UART_STAT_TFFU BIT(6) +#define OWL_UART_STAT_TRFL_MASK (0x1f << 11) +#define OWL_UART_STAT_UTBB BIT(17) + +static inline void owl_uart_write(struct uart_port *port, u32 val, unsigned int off) +{ + writel(val, port->membase + off); +} + +static inline u32 owl_uart_read(struct uart_port *port, unsigned int off) +{ + return readl(port->membase + off); +} + +#ifdef CONFIG_SERIAL_OWL_CONSOLE + +static void owl_console_putchar(struct uart_port *port, int ch) +{ + if (!port->membase) + return; + + while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TFFU) + cpu_relax(); + + owl_uart_write(port, ch, OWL_UART_TXDAT); +} + +static void owl_uart_port_write(struct uart_port *port, const char *s, + u_int count) +{ + u32 old_ctl, val; + unsigned long flags; + int locked; + + local_irq_save(flags); + + if (port->sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&port->lock); + else { + spin_lock(&port->lock); + locked = 1; + } + + old_ctl = owl_uart_read(port, OWL_UART_CTL); + val = old_ctl | OWL_UART_CTL_TRFS_TX; + /* disable IRQ */ + val &= ~(OWL_UART_CTL_RXIE | OWL_UART_CTL_TXIE); + owl_uart_write(port, val, OWL_UART_CTL); + + uart_console_write(port, s, count, owl_console_putchar); + + /* wait until all contents have been sent out */ + while (owl_uart_read(port, OWL_UART_STAT) & OWL_UART_STAT_TRFL_MASK) + cpu_relax(); + + /* clear IRQ pending */ + val = owl_uart_read(port, OWL_UART_STAT); + val |= OWL_UART_STAT_TIP | OWL_UART_STAT_RIP; + owl_uart_write(port, val, OWL_UART_STAT); + + owl_uart_write(port, old_ctl, OWL_UART_CTL); + + if (locked) + spin_unlock(&port->lock); + + local_irq_restore(flags); +} + +static void owl_uart_early_console_write(struct console *co, + const char *s, + u_int count) +{ + struct earlycon_device *dev = co->data; + + owl_uart_port_write(&dev->port, s, count); +} + +static int __init +owl_uart_early_console_setup(struct earlycon_device *device, const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = owl_uart_early_console_write; + + return 0; +} +OF_EARLYCON_DECLARE(owl, "actions,owl-uart", + owl_uart_early_console_setup); + +#endif /* CONFIG_SERIAL_OWL_CONSOLE */